The purpose of this Program Project jointly planned by six staff members of the Laboratory of Lipid and Lipoprotein Studies, Oklahoma Medical Research Foundation, is to provide new information about the chemistry, physiology and clinical signficance of plasma lipoproteins and to utilize the existing and newly acquired knowledge for the formulation of a general theory of lipid tranpsort processes. The conceptual framework of the entire program is based on the view that apolipoproteins are the most probable determinants of the structural stability and functional specificity of lipoproteins. According to this conceptualization, the fundamental physical-chemical entities of this system are lipoprotein families defined solely in terms of their constituent apolipoproteins. The chemical studies will be concerned with the characterization of human and turkey apolipoproteins and lipoproteins, and development of new procedures for the isolation, purification and quantification of free ("primary lipoproteins") and associated ("secondary lipoproteins") forms of lipoprotein families (Projects 1, 3 and 5). The metabolic studies will be concerned with factors and conditions that regulate the formation (Project 3) and degradation (Project 4) of free and associated forms of lipoprotein families, while studies on the interaction of lipoprotein and cellular surfaces (Projects 5 and 6) will explore the specific role and function of lipoproteins as the potential donors and/or acceptors of lipids. Results of these studies will be utilized for the biochemical identification and characterization of defective lipid transport processes in various types of dyslipoproteinemias (Project 7). Once established, the characteristic concentration profiles of free and association forms of lipoprotein families may be used for diagnostic purposes, as indicators of developing atherosclerotic disease and as a sensitive means for monitoring the progress of therapeutic interventions designed to normalize plasma lipoprotein levels or underlying metabolic defects in patients with primary and secondary hyperlipoproteinemias.